Video teleconferencing typically uses a small number of microphones and cameras (for example, one microphone and one camera) to capture multiple participants. Each participant is represented by only a small number of pixels, and image quality can often be degraded by compression techniques used to conserve bandwidth. The combination of image size and degraded quality typically impacts image resolution such that an identity of a participant can be difficult to discern. More subtle interpersonal nuances like facial expression and degree of attentiveness can be still more difficult to discern. Further, audio gain must be set relatively high on a shared microphone in order to pick up participants at a distance of several feet or more from the microphone. Higher gain can result in acoustic feedback when the microphone picks up amplified signals from a remote location, which contain the local microphone signal.
The use of microphone arrays (or other sensors) is known in the art for reducing background noise and for identifying a location of an acoustic source. For example, U.S. Pat. No. 5,737,431 discloses a method for de-emphasizing sounds peripheral to a particular location and for steering a camera for use in a video teleconferencing system to a particular participant or other acoustic source. Such camera steering techniques are applied so that a single camera can capture multiple participants positioned in a large room, for example. These techniques fail to address the effectiveness of communication between participants as a function of image quality and scale.
The use of one-to-one terminals is known in the art for improving communication between a single remote participant and a single local participant. For example, U.S. Pat. No. 4,928,301 discloses a teleconferencing terminal which enables teleconference participants to make eye contact while communicating. Such techniques limit the number of participants in communication at a single time, and limit the nonverbal communication between participants, making a video teleconference with more than two participants cumbersome and difficult.